/* Copyright (C) 2000 MySQL AB

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */

#include "mysys_priv.h"
#include <m_string.h>
#include "my_static.h"
#include "mysys_err.h"
#include <errno.h>
#ifdef HAVE_PATHS_H
#include <paths.h>
#endif

#ifdef HAVE_TEMPNAM
#if !defined(MSDOS) && !defined(OS2) && !defined(__NETWARE__)
extern char **environ;
#endif
#endif

/*
  Create a temporary file in a given directory
  This function should be used instead of my_tempnam() !
*/

File create_temp_file(char *to, const char *dir, const char *prefix, int mode __attribute__((unused)),
                      myf MyFlags __attribute__((unused)))
{
  File file = -1;
  DBUG_ENTER("create_temp_file");
#if defined(_MSC_VER)
  {
    char temp[FN_REFLEN], *end, *res, **old_env, *temp_env[1];
    old_env = environ;
    if (dir)
    {
      end = strend(dir) - 1;
      if (!dir[0])
      { /* Change empty string to current dir */
        to[0] = FN_CURLIB;
        to[1] = 0;
        dir = to;
      }
      else if (*end == FN_DEVCHAR)
      { /* Get current dir for drive */
        _fullpath(temp, dir, FN_REFLEN);
        dir = to;
      }
      else if (*end == FN_LIBCHAR && dir < end && end[-1] != FN_DEVCHAR)
      {
        strmake(to, dir, (uint)(end - dir)); /* Copy and remove last '\' */
        dir = to;
      }
      environ = temp_env; /* Force use of dir (dir not checked) */
      temp_env[0] = 0;
    }
    if ((res = tempnam((char *)dir, (char *)prefix)))
    {
      strmake(to, res, FN_REFLEN - 1);
      (*free)(res);
      file = my_create(to, 0, mode | O_EXCL | O_NOFOLLOW, MyFlags);
    }
    environ = old_env;
  }
#elif defined(_ZTC__)
  if (!dir)
    dir = getenv("TMPDIR");
  if ((res = tempnam((char *)dir, (char *)prefix)))
  {
    strmake(to, res, FN_REFLEN - 1);
    (*free)(res);
    file = my_create(to, 0, mode | O_EXCL | O_NOFOLLOW, MyFlags);
  }
#elif defined(HAVE_MKSTEMP) && !defined(__NETWARE__)
  {
    char prefix_buff[30];
    uint pfx_len;
    File org_file;

    pfx_len =
        (uint)(strmov(strnmov(prefix_buff, prefix ? prefix : "tmp.", sizeof(prefix_buff) - 7), "XXXXXX") - prefix_buff);
    if (!dir && !(dir = getenv("TMPDIR")))
      dir = P_tmpdir;
    if (strlen(dir) + pfx_len > FN_REFLEN - 2)
    {
      errno = my_errno = ENAMETOOLONG;
      DBUG_RETURN(file);
    }
    strmov(convert_dirname(to, dir, NullS), prefix_buff);
    org_file = mkstemp(to);
    file = my_register_filename(org_file, to, FILE_BY_MKSTEMP, EE_CANTCREATEFILE, MyFlags);
    /* If we didn't manage to register the name, remove the temp file */
    if (org_file >= 0 && file < 0)
    {
      int tmp = my_errno;
      (void)my_delete(to, MYF(MY_WME | ME_NOINPUT));
      my_errno = tmp;
    }
  }
#elif defined(HAVE_TEMPNAM)
  {
    char *res, **old_env, *temp_env[1];
    if (dir && !dir[0])
    { /* Change empty string to current dir */
      to[0] = FN_CURLIB;
      to[1] = 0;
      dir = to;
    }
#ifdef OS2
    /* changing environ variable doesn't work with VACPP */
    char buffer[256], *end;
    buffer[sizeof(buffer) - 1] = 0;
    end = strxnmov(buffer, sizeof(buffer) - 1, (char *)"TMP=", dir, NullS);
    /* remove ending backslash */
    if (end[-1] == '\\')
      end[-1] = 0;
    putenv(buffer);
#elif !defined(__NETWARE__)
    old_env = (char **)environ;
    if (dir)
    { /* Don't use TMPDIR if dir is given */
      environ = (const char **)temp_env;
      temp_env[0] = 0;
    }
#endif
    if ((res = tempnam((char *)dir, (char *)prefix)))
    {
      strmake(to, res, FN_REFLEN - 1);
      (*free)(res);
      file = my_create(to, 0, (int)(O_RDWR | O_BINARY | O_TRUNC | O_EXCL | O_NOFOLLOW | O_TEMPORARY | O_SHORT_LIVED),
                       MYF(MY_WME));
    }
    else
    {
      DBUG_PRINT("error", ("Got error: %d from tempnam", errno));
    }
#if !defined(OS2) && !defined(__NETWARE__)
    environ = (const char **)old_env;
#endif
  }
#else
  {
    register long uniq;
    register int length;
    my_string pos, end_pos;
    /* Make an unique number */
    pthread_mutex_lock(&THR_LOCK_open);
    uniq = ((long)getpid() << 20) + (long)_my_tempnam_used++;
    pthread_mutex_unlock(&THR_LOCK_open);
    if (!dir && !(dir = getenv("TMPDIR"))) /* Use this if possibly */
      dir = P_tmpdir;                      /* Use system default */
    length = strlen(dir) + strlen(pfx) + 1;

    DBUG_PRINT("test", ("mallocing %d byte", length + 8 + sizeof(TMP_EXT) + 1));
    if (length + 8 + sizeof(TMP_EXT) + 1 > FN_REFLENGTH)
      errno = my_errno = ENAMETOOLONG;
    else
    {
      end_pos = strmov(to, dir);
      if (end_pos != to && end_pos[-1] != FN_LIBCHAR)
        *end_pos++ = FN_LIBCHAR;
      end_pos = strmov(end_pos, pfx);

      for (length = 0; length < 8 && uniq; length++)
      {
        *end_pos++ = _dig_vec_upper[(int)(uniq & 31)];
        uniq >>= 5;
      }
      (void)strmov(end_pos, TMP_EXT);
      file = my_create(to, 0, (int)(O_RDWR | O_BINARY | O_TRUNC | O_EXCL | O_NOFOLLOW | O_TEMPORARY | O_SHORT_LIVED),
                       MYF(MY_WME));
    }
  }
#endif
  if (file >= 0)
    thread_safe_increment(my_tmp_file_created, &THR_LOCK_open);
  DBUG_RETURN(file);
}
